The broad program is to define the nature of acquired immunity in tubercolosis. We have developed a non-viable, non-allergenic vaccine against tuberculosis hopefully suitable for use in man. These methods have been used to develop vaccines against other infectious diseases. This material contains ribosomal RNA. To continue our studies on the nature of the labile, immunizing substance found in the RNA fraction prepared from ruptured viable attenuated mycobacteria. To continue our studies on the role of the lymphocyte in immunity to tuberculosis and other diseases due to facultative intracellular parasites. To isolate and identify the filterable mycobacterial growth inhibitory substance(s) (MycoIF) produced by lymphocytes obtained from immunized mice which brings about inhibition of growth of virulent tubercle bacilli within macrophages in tissue culture. To determine the relationship of MycoIF to other lymphocyte products. To continue our studies on the effect of myc. RNA on the progression on tumors in mice.